デコンボリューション法の適用によるパンタグラフ空力音の推定法

抄録

Aerodynamic noise generated from pantograph of Shinkansen train is one of the important sources of Shinkansen railway noise. De-convolution (DC) method with microphone array is widely used for source localization in a wind tunnel test to develop noise mitigation methods effectively. The point spread function (PSF) which gives the response of a noise source affects the result of DC method. This paper describes a method to estimate sound pressure level (SPL) of aerodynamic pantograph noise at an arbitrary observation point based on the sound source map obtained by the deconvolution method. PSF, which is designed with the effect of sound field around the pantograph is calculated by numerical analysis (boundary element method). The properties of the calculated PSF is examined in by a speaker test by comparing with a result obtained by conventional PSF, which is designed for a free space. The proposed method is applied to the measurement of the aerodynamic pantograph noise in a wind tunnel test. It is shown that the estimated SPL of the pantograph noise at the observation points agrees well with the measurement result and spatial resolution of the source localization can be improved.